Lets do the same calculations, just with time passed since the first release:
First episode came out in september 2023.
It took 28 months for a second season to get released.
That is 1 episode ~ 2 chapters / month. (We are currently at the begining of volume 7: chapter 60)
By that pacing logic:
Season 2: up untill mid volume 9 (~20 episodes)
Season 3 would due at november 2026 (till volume 11), and Season 4 at september 2027 (till mid/end volume 13)
And we would still have 2 chapters for a season 5 to get released in 2028 summer.
I personally could live with that, but it won´t happen: that means 2.5 years for the creators to get healty, and start producing at least 2-3 chapters pro year, and with a concept in mind... And Madhouse still wont have enough time to catch up.
